Compared with other services, I usually found the stats given by StatCounter having bigger values for Firefox (have no idea about their, or others, methodologies), this is why I don't take the exact numbers as absolute but was looking at the trends. The latest report, which made the rounds in the tech press is showing how worldwide Chrome slightly overtook Firefox (with half a percent) and both of them added are way above Internet Explorer (10 percents). This pretty much mirrors my anecdotal evidence of seeing IE mostly on the computers of the most clueless users, Firefox on those installed by a knowledgeable friend or admin and Chrome used more and more by simple-to-average users and even techies.
Point of view
4 days ago